1. Technical Field
This disclosure generally relates to tactile human-machine interfaces, such as buttons, knobs, dials, etc, and more particularly to an interface or control that utilizes active material actuation to change a first geometric shape, orientation, position or otherwise characteristic of the interface.
2. Background Art
Human-machine interfaces (HMI's) have long provided facilitating means for entering user-generated input into a communicatively coupled system. Among these, tactile interfaces, such as buttons, knobs, dials, etc., allow a user to manually enter an input. For example, in an automotive setting, knobs are often rotated by a user to change an aspect of a telematic, entertainment, diagnostic, wiper, or HVAC system. That is to say, manipulation of a volume knob may resultantly cause a potentiometer to slide, thereby increasing or decreasing power to the speaker system and volume.
It is appreciated by those of ordinary skill in the art, however, that the use of conventional tactile HMI's present various concerns in the art; for example, as exemplified in an automotive setting, the user is often required to temporarily draw his or her attention away from a main task, such as properly operating the vehicle, in order to distinguish amongst a plurality of similarly sized and shaped HMI's. In a dimly lit or dark space (e.g., the interior cab of a vehicle while driving at night) selecting the desired interface may be further obfuscated. Once selected, it is known in the art to release a detent or latch by depressing the HMI, so as to cause it to extend towards a more readily manipulated position; however these configurations require even more attention than static HMI's. Of further concern, it is also appreciated that engagement between a variety of user hand sizes and a one-size-fits-all HMI configuration often results in a tactile HMI that is difficult to manipulate for certain users.